Typical boxes are sized to securely accommodate an entire product or an article in order to prevent the contents of the box from damage by shaking or impact which might be caused by vacant space in the box. Therefore, general boxes have a narrow space, and it is difficult to put in articles or take out articles from the box in a simple and easy way when there is a tight fit. Furthermore, disposable products are most commonly used as a box for packaging food products or articles. Particularly, in case of boxes for convenience foods such as hamburgers or pizzas, the boxes are discarded without any recycling. For example, in case of pizza slices, the boxes can't be used as plates. Instead, additional dinner plates are necessary in order to serve the pizza slices to people. As consumer's preferences have been highly diversified, it is desirable to provide a box that overcomes the above-described problems and disadvantages in order to meet an increasing desire or convenience of consumers.